1. Field of the Invention
This invention pertains to forms for use in casting concrete walls, and more particularly to a removable casting frame or window pour mold for forming a window opening through a concrete wall such as a basement wall, for receiving a window, wherein the window can be installed by its frame or a flange on the frame, sealingly in the wall without need for a window sub-frame precast in the concrete.
2. Description of the Prior Art
FIG. 1 is a cross section partial schematic view of a PRIOR ART window pour mold.
FIG. 2 is a cross section partial schematic view of the PRIOR ART window pour mold of FIG. 1. Cross hatch is omitted for clarity.
FIG. 3 is a cross section partial schematic view of the PRIOR ART wall opening formed by the window pour mold of FIG. 1.
In FIG. 1, PRIOR ART window pour mold 100 is mounted to wooden wall mold 102 that is used to cast a basement wall so that when the concrete is poured, a concrete wall is created with the window pour mold set in the concrete wall. Window pour mold 100 is attached to wall mold 102 by nails 106 which extend through metal mounting brackets 110 into the wood.
When the window pour mold is removed from the hardened or set concrete wall, it leaves behind wall opening 126 in concrete wall 130. Outer wall 120 of pour mold 100 establishes the final shape of inner wall 124 of wall opening 126.
Outer wall 120 is a one piece aluminum extrusion having a fixed shape for a predetermined wall thickness. Outer wall 120 extends around all four sides, top, bottom, left and right, of window pour mold 100. For clarity of description, only the top side is shown. Step 136 forms step 138 on inner wall 124 for seating a window sealing flange so that the window is set into opening 126 almost midway between front face 140 and back face 142 of concrete wall 130, where front face 140 is the outside of the building and back face 142 is the face on the inner room side of the building.
Referring to FIGS. 2, and 3, PRIOR ART pour mold 100 is withdrawn 132 from opening 126. During removal, friction between the concrete inner wall 124 and the window pour mold outer wall 120 extends almost the length 128 of opening 126, because the mass of the fluid concrete presses on outer wall 120 from all four sides, top, bottom, left and right, so that the pour mold springs in slightly. When the concrete hardens it grips the outer walls of the pour mold.
Friction is especially high for window mounting area 162 which includes the space in which main frame 164 of window assembly 160 locates at one end of the window mounting area and its distance from back face 142. The friction also extends along back leg 144 length 146, 146a, and most of front leg 148 length 150, 150a.
In FIG. 3, window assembly 160 is installed in PRIOR ART opening 126 through concrete wall 130. It is set back by distances 166 and 168 respectively from front and back face 140 and 142 of wall 130. The ratio of distance 166 to 168 in prior art constructions ranges from 0.75 to 1.5.
Rain water 170 with dirt washes down face 140, and moves along under inner wall 124 PRIOR ART shape formed by PRIOR ART pour mold 100, and down over window glass 174 as shown by direction arrow 176. From inside a room of the building, an upward angle 172 view must be taken from a very low 178 vantage point 180 compared to level view 184 vantage point 186.